Spring 2020 – Ex Ovo Optimization

Although conventional animal models used to study intact vascular networks have been optimized for mature subjects, models to study embryonic development have yet to be fully established. Great challenges remain, including the need for refined surgical techniques, multiple survival surgeries and related animal care, and the need for dedicated and customized equipment. Furthermore, most embryonic models have low rates of viability after interventions and can be cost-prohibitive for many research groups. The chick chorioallantoic membrane (CAM) model shows great promise as an alternative model for microvascular research, and has already been used extensively to study angiogenesis in relation to tumor growth. However, conventional windowing methods limit the study of a developing vascular network. The present work focuses on developing an ex-ovo CAM model optimized for intravital vascular studies. Three critical constraints have been identified that must be met: 1) environmental constraints: regulating temperature, humidity and oxygen levels for extended periods outside of the incubation chamber, 2) visualization constraints: ensuring planar surface and access to an entire vascular network for intravital microscopy, and 3) incubation constraints: maintaining sterility during measurements. Furthermore, to make this animal model widely accessible to investigators studying development of the vasculature over time, strategies must be developed to minimize cost and maximize reproducibility and scalability.